The Mars Express took this photo of a crater on Mars filled with water ice. Credit: ESA/DLR/FU Berlin (G. Neukum)

Ice is common in our solar system, from deposits at the poles of Mercury and the Moon to ice-covered moons and rings around distant Jupiter and Saturn, and comets made of ice and other materials streaming across the spaces between. And, of course, ice is present around our own world.

The ice on continents contains about 75% of Earth'sfreshwater. Melting ice sheets on Greenland and Antarctica have the potential to raise global sea levels by 23 feet (Greenland) and 187 feet (Antarctica).

While the most common type of ice in our solar system is water ice, there are also many other types of ice. Mars' poles have abundant amounts of frozen carbon dioxide (also called dry ice), and comets have frozen ammonia and methane in addition to frozen water and other ices. Saturn's moon Titan is famous for its methane, which can exist as a solid, a liquid and a gas at Titan's surface temperatures and pressures.

Scientists are studying water ice both on Earth and on other planets; snow and glaciers are a critical source of freshwater for many regions on Earth, and ice deposits can be a source of water for future explorers in the solar system. Given the apparent need all life has for water, the presence of frozen water may also provide clues to the possibility of life! For more about water's presence and role on the planets, check out the YSS topic Water in the Solar System; check out Got Life for more about the search for life.

All types of ice play an important role in the characteristics and planetary processes throughout the solar system. Glaciers have eroded parts of the Earth and Mars, creating new features. Uranus and Neptune are filled with "icy" materials like water, ammonia, and methane, under incredible heat and pressure. Some moons in the outer solar system have volcano-like geysers that erupt ice! For more information about ice in the solar system, check out Background.

Examine this topic as we explore ice and its properties, where it is located, and what it tells us about the planets and moons in our solar system. Check out the classrooms and informal activities and the resources sections for further information!